The invention relates to a device allowing performance of spinal stabilisation by a screw-type bone anchoring element via the posterior or posterolateral approaches.
The device according to the invention is designed particularly, but not exclusively, for lumbar, thoracic or furthermore posterior cervical spinal osteosynthesis via minimally invasive or open surgical approaches.
In the conventional method in itself, in case of anatomical dysfunctions of the vertebral column, pedicle screw-type bone anchoring elements are inserted (installed) in the vertebrae, interconnected by rod-type or plate-type connecting elements.
The state of the art in the field of vertebral column surgery involves providing hospitals with implants and sets of instruments for their insertion (installation). Some companies specialised in the field supply ready-to-use, sterile packed implants. The sets of instruments reusable after decontamination and sterilisation present many disadvantages. The risk of interpatient contamination is very high; cleaning, decontamination and sterilisation are steps which are sometimes almost impossible to perform correctly in view of complex designs with many cavities inside the instruments. These steps are a financial burden for the hospitals and represent very high costs, both in human and material terms.
Loss, breakage, wear and damage of an instrument may result in disastrous consequences for the patient or even cause cancellation of the surgery. The logistics also present many disadvantages; cumbersome and costly both for the industrialist and the hospital, they most often involve significant inventories. Indeed, since surgeons only operate two days a week in the majority of cases, the number of sets of instruments made available to the hospital depends on the activity, with traumatology operations being added if necessary to the surgical programme.
The rotations of sets between the hospital and the industrialist's logistics service are therefore very large in number, which significantly increases the risks of losses and errors.
In other surgical fields, in order to take account of the safety aspect both for the patient and surgeon, the financial, human and material aspect for the hospital in addition to the service offered and expected by the industrialist's customers, it has been proposed to shift towards disposable “all sterile” surgery. International application WO 98/22035 is known for example. The latter describes a kit of surgical instruments, manufactured economically from synthetic sterile material. This type of kit is marketed for genecological or microsurgical operations. These generic instruments of the scissor, dissection plier or furthermore scalpel type are not intended for insertion of an orthopaedic implant and are not caused to undergo high mechanical stresses. Transformation of a metallic instrument to disposable polymer is known in many medical fields.
International application WO 2005/016183 is also known. It describes an implant kit of the vertebral plate and screw type combined with disposable sterile packed instruments. Apart from the disadvantage of only offering a single screw length and diameter for the bone anchoring, this method only describes a single type of instrument: a screwdriver shank and its handle. This international application does not offer any technical solution for designing and manufacturing instruments subject to major stresses such as the vertebral distractor which is absolutely essential for inserting the implant.